Could you please describe your application: /n_HUY 1, is the emitting source single mode or multimode? what are the parameters i.e. divergence, waist, ... Kc{wv/6}T 2, is the fiber single mode or multimode? what is the NA, core dia,... tIvtiN6[|l n+i}>3'A Generally, fiber coupling efficiency of 40%~90% is reasonable. G![1+2p:Tq !{3pp Again let us know your specific bug. l`u*,"$ 7v:;`6Jb MANG2004 . }1!MK5